Our long term goal is to identify the earliest stages of lens opacification in which the reversal of the cataract may be possible. This could lead to the development of methods to improve transparency in human lenses at the early reversible cataract. A major concern is that morphological and biochemical canges due to the early of opacification are difficult to distinguish from changes due to normal aging. The objective of this proposal is to develop sensitive new quantitative techniques to characterize the parameters associated with cell aging and those associated with early stages of opacification. We will use laser light scattering spectroscopy to differentiate light scattering properties of normal lens aging from light scattering behavior which leads to cataract. In order to study cellular restructuring due to aging and the initial restructuring of opacifying lens cells, we will develop a unique methods of image analysis of electron micrographs. This method will be capable of identifying the subtle morphological changes which lead to the formation of light scattering elements in lens cells. In additon, we will apply high pressure liquid chromatography as a new and highly sensitive method for the analysis of biochemical constituents in aging cells and in developing cataracts. The results of these studies will be used to evaluate the initial morphological and biochemical changes in lens fiber cells that accompany the early stages of cataract development and to differentiate these changes from those which are due to the normal aging process.